Jan 31 LUNAR ECLIPSE

09/01/18 14:29

At the risk of adding to the “super Moon” hype, allow me to point out that both full Moons in January are “super”. The Jan 1 full Moon is more super than the full Moon at month-end by a mere 2 429 km, but the full Moon on Jan 31 is also a so-called “blue” Moon. Adding to the hype, the Moon is supposed to turn “blood red” during a lunar eclipse that morning. So on Jan 31, we are due for a Super, Blue, Blood Red Moon! Sheesh.

The “blood red” label appears to be a relatively recent development, a result of two prophets of doom that thought four lunar eclipses in a row (ending with the Sep 27, 2015 eclipse) meant something special. It did not. The apocalypse did not happen in 2015, just like the other 20 times doomsday was predicted since Jan 1, 2000. By the way, there are three dates (so far) on which the world will end in 2018. I would watch out for the doomsday of May 20, a date supposedly guaranteed in the Bible (or your money back).

The Earth’s shadow in space has two parts, a dark circular core called the umbra, which is about 3 times the diameter of the Moon, and an invisible outer shadow called the penumbra which is even larger. It is only the umbra that we see progressing across the Moon during an eclipse, making it appear to go through its monthly cycle of phases in a just a few hours. See our website www.bluewaterastronomy.com for a neat graphic depicting this.

Moon colour during lunar eclipses is caused by our atmosphere filtering out blue light the same way it does whenever the Moon or Sun are near the horizon. For any of the lunar eclipses I have seen, “blood red” would not be a colour description I would have used. I have seen “reddish-brown”, “orange”, “yellowish-orange”, and even “gray” the one time that volcanic ash in our atmosphere filtered out all the colour from the light getting to the Moon. That time, the eclipsed Moon was invisible to the naked eye and only just detectable in binoculars, appearing like a black hole among the stars. Furthermore, the central part of Earth’s shadow is darker so the Moon’s colour changes as the eclipse progresses. Colour-wise, no two lunar eclipses are ever exactly the same and hardly ever do we see “cherry” or “blood red” colours, -except after some Photoshop “enhancement” also known as “astro-fake-it-ography”.

The total lunar eclipse just before sunrise on Jan 31, 2018 will be visible all over the western hemisphere more or less. For us here in Bruce and Grey county, it will be less than more. Folks in the Prairie provinces get more, and those farther west in Calgary or Kelowna, for example, will see the entire event.

The hour-long passage of the full Moon through Earth’s shadow is the most interesting part of a lunar eclipse, but unfortunately this time, all of eastern Canada misses it. Locally, the Moon sets below our western horizon 10 minutes before totality begins and we will see only a bright “crescent” Moon with a bit of redness to the darkened portion like the image provided here of the Sep 27, 2015 lunar eclipse. Seeing conditions will have to be perfect to see anything like this and the Moon will be dimmed because sunrise is at the same time as moonset.

For Bruce-Grey, the first umbral contact occurs at 6:48 am EST with the full Moon only 8 degrees above the western horizon (about the width of your out-stretched hand). A darkening at upper left should be noticeable by 6:45 am or so and it will progress across the Moon until the Moon sets at 7:44 am EST below our western horizon. For those in the Pacific Time Zone, totality starts at 4:52 am PST (7:52 EST), and lasts for 76 minutes until 6:08 PST. The eclipse ends when the last bit of the full Moon reappears by 7:11 am PST. You need to be west of the Manitoba-Saskatchewan border to see all of totality before the Moon sets.

The Bluewater Astronomical Society will make the best of the event locally with telescopes at a location with a good view to the western horizon. We will be scouting locations along the Lake Huron shore where snowbanks are manageable. Assuming weather co-operates, check our website www.bluewaterastronomy.com as the time approaches for last-minute confirmation of viewing site. Fingers crossed for clear skies!